North America

SIP Trunk United States — +1 Termination & DID Numbers

US termination is judged on attestation as much as price: since the FCC's STIR/SHAKEN mandate, calls with weak or missing attestation are far more likely to be labelled spam or silently blocked. We route US traffic over carriers that sign calls, and we only accept caller IDs you can show you are entitled to use.

Get United States rates Talk to NOC

Overview

Routing calls to United States

Traffic to United States leaves our SBCs on more than one upstream carrier per prefix. If a leg toward New York or Los Angeles starts returning 503s or long post-dial delay, the next attempt goes to another carrier automatically. Calls to Chicago, Houston, Miami and Dallas follow the same failover logic.

Numbering in United States is managed by FCC. We terminate to geographic, mobile and toll-free ranges and price each one separately on the rate sheet. Inside the country, numbers are dialled with a 1 trunk prefix. Strip it before you send the call, and send 1 followed by the national number.

Documentation for United States DIDs depends on the range. Some go live with standard account details, and others need a local address. Outbound calling has no extra requirements.

What you get

What you get in United States

One account and one balance, with the same SBCs for termination and inbound numbers.

CLI route tier
Caller ID delivered end to end on +1 calls. Use it for sales, support and any traffic where answer rates matter.
Non-CLI route tier
A lower-cost tier where caller ID delivery is not guaranteed. Suitable for internal or transactional traffic that does not depend on the CLI.
Number types
Geographic, Mobile, Toll-free. DID availability varies by range and city.
Codecs
G.711a/u and G.729 on every route, G.722 and Opus where the far end supports them. T.38 for fax.
Channels on demand
Concurrent call limits are set per account and raised as your traffic grows. No fixed channel bundles.
Multi-carrier failover
Every +1 prefix is mapped to more than one carrier. Failed attempts move to the next one automatically.

Number formats

How to dial United States from your PBX

Send E.164 digits. The sample number below shows the format only.

United States number formats
Format	Example	Notes
International (E.164)	+1 202 555 0142	How the number is written and stored.
Sent from your PBX	12025550142	E.164 digits with no plus, prefixed by your tech prefix if your account uses one.
With 00 exit code	00 1 202 555 0142	Accepted on the trunk. We normalise it to E.164.
National format	1 202 555 0142	Dialled inside United States. Strip the trunk prefix before sending.

Compliance

United States rules to know

What applies before your first call or your first DID goes live.

Compliance box

Regulator: FCC
Caller ID: A valid CLI that you are entitled to use is required on CLI routes. Spoofed or unallocated numbers are blocked.
DID KYC: Sometimes required
Note: STIR/SHAKEN applies to all US-originated calls. Unsigned or C-attested calls see lower answer rates.
Note: Valid, assigned CLI is mandatory. The TCPA governs autodialled and prerecorded calls.

Rules change — our team confirms current requirements before activation.

Spam, robocalls and fraud are not allowed. Read our acceptable use policy.

Use cases

Who uses United States routes

01
Outbound sales and appointment-setting teams that need A-level attestation on owned DIDs
02
Offshore support centres serving US customers on local area codes
03
Toll-free inbound lines (800, 833, 844, 855, 866, 877, 888) routed to a cloud PBX

Setup

Start calling United States in 3 steps

01
Top up $200
Open a prepaid account and add balance by USDT (TRC20), BTC or card.
02
Add your trunk
Whitelist your PBX IP or create digest credentials, then point your outbound route at our SBC.
03
Dial +1
Send 1 + national number in E.164 and check the CDR for your first test call.

PBX guides:Asterisk setup guide 3CX setup guide All guides

Further reading: SIP Trunk USA: Routes, CLI and Compliance Guide

FAQ

United States SIP trunk questions

Will my US calls be signed with STIR/SHAKEN?

Calls that present a US number assigned to your account are signed by the originating carrier. The attestation level depends on how the number is held. Numbers you port in or buy from us get the strongest attestation.

Can I present any US caller ID?

No. The CLI must be a number you own or are authorised to use. Spoofed or unassigned CLIs breach our acceptable use policy and will be blocked.

Do you support TCPA-regulated dialling?

We carry the calls; you are responsible for consent, calling hours and Do Not Call scrubbing under the TCPA and state rules. Robocall or predictive campaigns without consent are not allowed on our network.